Information released by Nintendo states that as of July 7th, 10 days after the game's release, 242 players have gathered over a million coins, and altogether over 10 billion coins have been collected globally (10,537,297,374 to be exact). Apparently, scores are sent automatically to Nintendo via the network capabilities of the 3DS and 3DS XL, where they are counted and announced via SpotPass. (This means that these numbers do not include players who have the SpotPass features of their consoles turned off.)

While these numbers are "global," Super Mario Bros 2 has only been released in Japan so far, so we can expect them to skyrocket come August 19th when the game hits stores stateside.